Dividend aligning mechanism



Sept. 29, 1953 G. c. ELLERBECK DIVIDEND ALIGNING MECHANISM 9 Sheets-Sheet 1 Filed Dec. 22, 1948 INVENTOR. BY GRANT C. ELLERBECK Sept. 29, 1 53 G. c. ELLERBECK 2,653,752

DIVIDEND ALIGNING MECHANISM Filed Dec. 22, 1948 9 Sheets-Sheet 2 IN V EN TOR.

GRANT C. ELLERBECK P 1953 G. c. ELLERBECK 2,653,762

DIVIDEND ALIGNING MECHANISM Filed Dec. 22, 1948 9 Sheets-Sheet 3 W E I;

INVENTOR.

GRANT C. ELLERBECK Sept. 29, 1953 G. C. ELLERBECK DIVIDEND ALIGNING MECHANISM 9 Sheets-Sheet 4 Filed Dec. 22, 1948 INVENTOR. GRANT C. ELLEREECK Sept. 29, 1953 G. c. ELLERBECK 2,653,762

DIVIDEND ALIGNING MECHANISM Filed Dec. 22, 1948 9 Sheets-Sheet 5 INVEN TOR.

GRANT C. iLLERbfiCK Sept. 29, 1953 G. c. ELLERBECK DIVIDEND ALIGNING MECHANISM 9 Sheets-Sheet 6 Filed Dec. 22, 1948 H II @HEE INVENTOR. GRANT C. ELLeRaem BY P 1953 G. c. ELLERBECK 2,653,762

DIVIDEND ALIGNING MECHANISM Filed Dec. 22, 1948 9 Sheets-Sheet '7 N 6') Q N as Q 7 I I II II Fl F1E=E IN VEN TOR.

GRANT C. ELLER BECK BY Sept. 29, 1953 G c ELLERBECK 2,653,762

DIVIDEND ALIGNING MECHANISM Filed Dec. 22, 1948 9 Sheets-Sheet s FIIIUE 1EI IN VEN TOR.

GRANT C. LLLERBLQK Sept. 29, 1953 G. c. ELLERBECK DIVIDEND ALIGNING MECHANISM 9 Sheets-Sheet 9 Filed Dec. 22, 1948 INVENTOR. GRANT C. ELLERBECK BY &

H H EUHFEH.

Patented Sept. 29, 1953 DIVIDEND ALIGNING MECHANISM Grant 0. Ellerbeck, Hayward, Calif., assignor to Friden Calculating Machine Co., Inc., a corporation of California Application December 22, 1948, Serial No. 66,745

22 Claims. (Cl. 235-63) This invention relates to improvements in calculating machines and more particularly to a mechanism for automatically aligning the dividend and divisor as a prelude to an automatic division operation.

In all of the presently known and existing types of calculating machine which are provided with means for automatically controlling the functicning of the various mechanisms of the machine during division operations, it is first necessary for the operator of the machine to align the dividend and divisor. This is ordinarily done by visual inspection of the factors and manipulation of the shift keys until the factors are brought into alignment after which the division key is depressed and the automatic division operation begun. The purpose of the present invention is to eliminate the factor aligning step in division operations and to cause the factors to be automatically aligned after the division key is depressed.

It is, therefore, an object of the present invention to provide an improved automatic division mechanism for calculating machines which will cause the factors to be aligned and the dividend to be divided by the divisor in one continuous automatic operation.

Another object of the invention is to utilize the existing automatic division mechanism of the calculating machine in order to cause alignment of the factors prior to the outset of the actual dividing operation of one factor by another.

Another object of the invention is to so modify the existing division program control mechanism of a calculating machine as to cause this mechanism to serve as a factor aligning device as well as a structure for automatically controlling the division operation.

Another object of the invention is to provide a calculating machine with a program control device which is settable from an idle position to a factor aligning position and also to an automatic division position, the device being automatically moved from one position to another so as to cause the factors to be aligned and the dividend to be divided by the divisor in one continuous, uninterrupted operation.

Another object of the invention is to provide a mechanism for terminating the factor aligning operation and conditioning the machine for a dividing operation when the carriage reaches its end position.

Still another object of the invention is to provide means for stoppage of the machine by the conventional division stop lever while the factors are being aligned.

The present invention is concerned with these and other objects which will become apparent from the following description of a preferred embodiment of the invention as shown in the accompanying drawings in which:

Fig. 1 is a longitudinal sectional elevation through the machine showing the selecting and actuating mechanisms thereof together with the accumulator and revolutions counter which are mounted in the shiftable carriage of the machine.

Fig. 2 is a plan view showing the selecting and actuating mechanisms of the machine and also certain parts of the factor aligning mechanism.

Fig. 3 is a longitudinal cross-sectional view illustrating certain parts of the extended tenscarry mechanism.

Fig. 4 is a transverse sectional elevation taken along the line 44 in Fig. 3.

Fig. 5 is a view showing the mechanism mounted on the left-hand side of the control plate.

Fig. 6 is a view showing the mechanism mounted on the right-hand side of the control plate.

Fig. '7 is a rear view of a portion of the machine showing the means whereby the machine is controlled in division operations from the highest order numeral wheel of the accumulator.

Fig. 8 is a fragmentary plan view showing in greater detail a portion of the mechanism illustrated in Fig. '7.

Fig. 9 is a schematic view illustrating a portion of the modified program control mechanism of the machine.

Fig. 10 is a cross-sectional elevation taken along the line l0l0 in Fig. 2 showing certain of the mechanism utilized for controlling the machine in division operations from the highest order numeral wheel of the accumulator.

Fig. 11 is a fragmentary cross-sectional view showing certain details of the modified program control mechanism.

Fig. 12 is a fragmentary view similar to Fig. 9 but showing the parts in different positions.

Fig. 13 is a fragmentary view showing the means for preventing the termination of a division operation while the factors are being aligned.

Fig. 14 is a detail view taken along the line I4l4 in Fig. 5.

Although the invention is shown in connection with a calculating machine of the type disclosed in U. S. Patent No. 2,229,889, issued to Carl M. F. Friden on January 28, 1941, it is not intended that its use should be confined only to a machine of this type since it is evident that the underlying principles thereof may be advantageously applied to other types or designs of calculating machines.

3 Inasmuch as the basic machine in which the present invention is incorporated is fully shown and described in the above-mentioned Patent No. 2,- 229,889, only so much of the fundamental machine is hereinafter disclosed as is necessary for a complete understanding of the invention.

Similarly, the automatic division mechanism.

herein employed is essentially like that illustrated in U. S. Patent No. 2,327,981, issued to Carl M. F. Friden on August 31, 1943, and therefore only those parts of the automatic division mechanism which are directly concerned with thepresent invention will be shown and described in this application.

Selecting and actuating mechanisms As shown in Fig. 1 of the drawings, the calculating machine is enclosed by covers 213 and is provided with a base M to which is fastened a left side frame 52 and a right side frame 23 (see also Fig. 2). The side frames 22 and Rare supported in spaced relationship by means of crossbars 2 1, 25, 26 and 2?, which crossbars also serve to support much of the operating mechanism of the machine. On the rear of the machine is provided a transversely shiftable numeral wheel carriage 23 in which the accumulator numeral wheels 29 and revolutions counter wheels 39 are mounted. The carriage is providedwith a cover 3i having suitable apertures formed therein through which the wheels 29 and 39may be viewed. The values to be entered into the accumulator wheels 29 may be determined by means of a plurality of similar selecting mechanisms which are associated with amount keys 35 of the keyboard. For this purpose each bank of amount keys cooperates with a pair of similar value selecting slides 36 which are mounted for endwise movement on supporting links 3'5 (only one shown) and extend through suitable slots provided therefor in the forward crossbar 23.

Each selecting slide 38 is connected at its rear end-with a ten tooth selector gear 38 which is slidably and non-rotatably mounted ona longitudinally extendingsquare shaft 39 journalled in thecrossbars 2e, 25 and 2%. Hence, the longitudinal movement of the slides 35, as differentially determined by the numeral keys 35, serves to position the selector gears 38 in the path of a series of stepped teeth provided on an actuating cylinder itsecured to a shaft M journalled between the crossbar 2d and a transverse supporting bar 42. For each adjacent pair of keybanks there is provided one shaft i bearing a pair of actuating cylinders Each actuator shaft H end a slidably but non-rotatably mounted spool.

56 to which is secured a teh tooth add gear 5! and a ten tooth subtract gear 52, which gearsare adapted to cooperate with a similar ten tooth gear 53 secured to the lower end of each of the accumulator numeral wheel shafts 5t.

When the machine is at rest, the gears'53 li'e mid-way between the "gears 51 and 52so as to engage the add gears 5! with the gears 53.

4 permit lateral shifting movement of the carriage, the gears 53 in this case being free to pass through the space existing between gears 5i and 52.

In order to enable an amount set up on the keys 35 to be'added into the accumulator wheels 29 the spool 50 and gears 5i and may be shifted toward the rear of the machine so as to This shiftingof the gears is accomplished by means of a flat bar or'gate 55 extending transversely across the machine and lying within the space provided between the add-subtract gears 5i, 52. The gate 55 issuppor-ted at either end by a pair of similar arms 56 (only one shown) secured to a transverse gate shaft 57 journalled between the side frames 22 and 23. The shaft 57 may be rocked clockwise, as viewed in Fig. 1, in a manner hereinafter tov be described so as to cause engagemer t of the add gears 5|.with the gears 53' and alternatively the shaft may be rocked counterclockwise so as to result in engagement of the subtract gears 52 with the gears 53.

Tens-transfer mechanism Secured to the lower end of each of the nu meral wheel shafts 5 2- is a tens-transfer carn'tfl" which is adapted to cooperate with a transfer which carries a stud 62 which is" lever El journalled in a hollow frame bar 81:3 of the. carr'iage. The transfer lever 61 carries at its outer end apin 64 which lies between a pair, of flanges? provided on the hub of a tenstransfer gear 55'" add subtract gears 51 or 52 to the numeral wheel'- shaft 54. Whenever the accumulator wheel 29 in a lower order passes from 0-9 or 9-0 a nose on the associated transfer cam to will rock the transfer lever 65 and move the pin t l forwardly so as to move the transfer gear 35 in the next higher order into the path of an actuating toot-h" mounted on the associated shaft il. Thereby;

the square shaft 39 in the higher order will be given one step of movement over and above that imparted to the shaft by the associated actuating cylinder 49 and the higher order accumulator wheelie will-thus be advanced onestep's'o as to efiectthe carry from the lower'order to the 'nex-t' higher order as required. After the tens-transfer has been effected, the gear 65 will be restored to its :normal position on the shaft 39'by means of a restoring cam secured to the shaft t l for this purpose.

Revolutions counter As shown. in'Fig. 1, each of the revolutionscounter numeral wheels till is secured to alongitudinally extendingshaft it which is journalled at its'rear, end in the carriage frame bar 63-and at its forward end in a crossbar ii which forms a part of the framework of the carriage. Each-of the shafts 'iil-hassecured thereto a gear i2 whichis arranged to be actuated by a' revolutions.

counter actuating mechanism 53 so as to cause the numeral wheels cc to be operated in suc'ha manner as to provideacount of'the'cyclic'operationsof the calculating machine and toeals'o' cause a tens-transfer to be effected from one.-

order to the next higher order each'ti'mea wheel 39 passes through zero.

For a more complete disclosure of this 'mecha nism reference is made to Patent No. 2,229,889-

which covers the basic machine.

Plus and minus keys In order to effect positive and negative registrations in the accumulator the calculating machine is provided with a plu key 11 (Fig. 5) and a minus key 18, both of which are slidably mounted on a control plate 19 secured to the right side frame 23 by means of suitable screws and spacing sleeves. The keys H and 18 are provided with roller studs 80 and 8| respectively, which cooperate with inclined cam faces 82 and 33 respectively, provided on a gate setting slide 84. This slide is pivotally connected at either end to the upper ends of arms 85 and 90, the arm 85 being pivoted on the control plate 19 while the arm 90 is secured to the gate shaft 51. Hence, forward and rearward movement of the slide 84 serves to rock the gate shaft clockwise or counter-clockwise, as the case may be, and thereby serves to cause engagement of the add gears 5| or the subtract gears 52 with the gears 53. Hence, when the plus key TI is depressed, the stud 8t will engage with the inclined cam face 82 and cause the slide 84 to be moved rearwardly thereby causing clockwise rotation of the gate shaft 517 as viewed in Fig. 1 so as to condition the machine for an adding operation. In a similar manner, when the minus key 18 is depress d, the stud 8i will engage with the cam face 83 on the slide as and cause the shaft 5'! to be rocked counter-clockwise (Fig. 1) and thereby cause the subtract gears to be engaged with the gears 53 so as to condition the machine for a subtracting operation.

In order to initiate the operation of the driving mechanism of the machine when either key 71 or it is depressed, each of these keys is provided with a half-round stud 8B which is adapted to cooperate with an inclined face 81 provided in a cycle initiating slide 88. The rear end of this slide bears against a stud 89 so that when either of the keys is depressed the stud will be moved rearwardly so as to cause the clutch to be engaged and the motor contacts to be closed thereby initiating a cycle of operation. For a more complete disclosure of this mechanism reference is made to Patent No. 2,327,981. When the clutch is engaged and the motor energized the power shaft 45 will be rotated thereby driving the actuator shafts 4!, to which are secured the actuating cylinders 48, thereby causing the amount set up on the keys 35 to be run into the accumulator wheels 29 in either a positive or negative direction depending on which of the keys 1! or 18 is depressed.

C'arrz'age shift mechanism Means are provided for shifting the carriage 28 in either direction from one ordinal position to the other by power derived from the actuator shafts 4! under the control of a pair of shift keys (not shown). Reference is made to U. S. Patent No. 2,327,635, issued to Carl M. Friden on August 24, 1943, for a complete disclosure of the carriage shift mechanism and only so much of the mechanism will be shown herein as is necessary for a complete understanding of the present invention.

As is fully disclosed in the aforementioned patent, the right and left shift keys when depressed serve to engage the clutch and close the motor contacts so as to initiate cycling of the machine and also cause the right shift clutch or the left shift clutch, as the case may be, to be engaged and thus cause a shifting movement of the carriage in either a right-hand or a left-hand direc-' tion. As shown in Fig. 2, the rightmost actuator shaft 4| is provided at its rear end with an extension which drives a male clutch element which lies in axial alignment with a female clutch element 95 formed on the forward end of a gear sleeve 9'! which is journalled between the rossbar 25 and a bearing plate its secured to the bar 26 by means of suitable screws and spacer sleeves. In a similar manner, the second actuator shaft il from the right is extended rearwardly where it is provided with a male clutch element llil adapted for engagement with a female element I62 formed on the forward end of a gear sleeve Hi3 journalled between the crossbar 2% and bearing plate I00. The clutch elements 95 and iii! are arranged for axial sliding movement whereby they may be engaged with the elements 96 or 102 respectively and thereby cause the gear sleeves 97 or I03 to be driven by power derived from the transverse power shaft 45.

For the purpose of engaging the elements 95 and fill with their respective mating elements 955 or I52, a pair of push rods Hi8 and 109 are provided. As shown in Fig. 2, these rods are mounted for longitudinal sliding movement in the crossbars 24 and 25 and are normally urged toward the front of the machine by means of compression springs H6 located on the forward ends of the rods. Each rod is provided at its rear end with a shifting fork HI and H2 which forks engage between suitable flanges provided on the elements 95 and 10!. The push rod I08 and its are adapted to be moved rearwardly so as to cause engagement of one or the other of the shift clutches by means of arms I I3 and 1 M which are arranged to bear against the forward ends of the push rods. As shown in Fig. 1, the arm i it is secured to a sleeve 1 I 5 which is loosely journalled on a transverse shaft H6 journalled in the framework of the machine. The arm H4 is similar to the arm H3 and is secured to the shaft H5. By means not disclosed herein, but fully shown and described in Patent No. 2,327,- 635, depression of the left shift key causes the shaft Hi; to be rocked counter-clockwise as viewed in Fig. 1, thereby causing the push rod N19 to be moved rearwardly thereby establishing a driving connection from the power shaft 45 to the gear sleeve H13. In a similar manner the sleeve H5 is adapted to be rocked counterclockwise upon depression of the right shift key so as to cause rearward movement of the push rod I88 so as to connect the gear sleeve 9'! with the power drive. As fully disclosed in the previously mentioned patent, the gear sleeve I03 is connected by suitable gearing with a shift gear I28 which carries a pair of shift pins l2! which are adapted to engage with notches formed in a shift rack 22 (Fig. 1) mounted on the rear of the carriage. The gear sleeve 9'5 is likewise connected with the shift gear I20 through suitable gearing but also employs a wide idler gear I23 (Fig. 1) for causing the shift gear to be driven in a reverse direction.

It will be understood from the foregoing description. that the right and left shift keys and the associated shift mechanism related thereto provide means for shifting the carriage selectively in either direction from one ordinal position to another. If either of the shift keys be maintained in their depressed position for more than one cycle of operation of the machine, the shifting operation will be continuous through a number of ordinal positions corresponding to the number ofeycles for whichtheikeyis held down: Shifting movements of the carriage are also; adapted to be controlled automatically during division operations through an auxiliary mechanism which will be described'hereinafter;

Extended. tens fmnsfer mechanism In the present machine provision has been made for effecting a tens-transfer from one order of the accumulator to-the next throughout the entire capacity of the accumulator. This is accomplished by providing an auxiliary or outboard transfer mechanism Which is brought into play with respect to the accumulator numeral wheels which lie to the 'left'of the regular transfer mechanism of the machine. This auxiliary transfermechani'sm is normally disabled and is rendered effective only in the event of a transferoccurring in the highest order controlled by the :regular transfer mechanism of the machine. Also, -this mechanism is capable of being disabled order by order as the outboard numeral wheels are shiftedinboard so as to cause the outboard transfer mechanism to become active only with respectto-those orders of the'accumulator lying to the left of the, regular or inboard transfer mechanism of the machine. This auxiliary transfer mechanism is of the simultaneous type and is" controlled for. plus or minus operations by the add-subtractgate of the calculating machine.

lThe auxiliary transfer mechanism herein shown and, described is identical with that shown in PatentNo. 2,403,069, issued to Carl M. Friden et al.. on July 2, 1946 and reference is made: to this patent. for adetailed description of the complete mechanism.

As shown in Fig; 3, each accumulator wheel shaftfM-lying beyond the regular transfer mechanism of the machine is provided with a sensing disc, Hi; and'a tens-transfer actuatinggear I3I. The disc I38. isadfapted togbe. sensed by a sensing finger I32 whichis; arranged to control an actuating tooth I33 cooperating with the gear I3I in the next higher order of the accumulator. The finger I32 and. tooth I33 form a part of an actuator assembly which is supported on an actuator shaft I34 journalled" between the lefthand end plate I35- (see Fig. 4) of the carriage and a bracket I36. mounted on the framework of the carriage. The shaft. I34. is adapted to receive endwise'sh-ifting movement and also rotary oscillatory movement. by means of a mechanism later to be described and is arranged to impart these, movements to the sensing fingers I32 and the actuating'teeth F33 of the actuator assemblyin a. manner similar to that. fully described in the aforementioned patent.

As the carriage moves toward the right, as viewed'in Fig. 4, additional orders ofthe accumulator will be moved inboard and means is provided for disabling the auxiliary transfer mechanism'in each order as. it comes'within the range. of the; regular transfer mechanism of the machine. This; means includes a camming rail I3? mounted on the framework of themachine which is. adapted to. engage. with rolls I38 carried by pivoted coupling members I39 so as to uncouple theactuating teeth from the sensing fingers as theaccumulator wheels are moved inboard. The actuator teeth and sensing fingers are also provided with depending tails I40 and I II respectively, which, as they pass inboard, move behind the edge-o-f-a fixed rail I42 so as to restrain the operation of these parts? in their inboard positions.

Means is also provided for preventing p r tion of the outboard or auxiliary transfer mechanism except when a tens-transfer occursin the highest order of the accumulator. Thismeans comprising a tiltable blocking member I43 which liesin the plane of the rail M2 and immediately to the left thereof, as seen in Fig. 4, so as to en gage the tail Hill of the actuating tooth associated with the lowest outboard order thereby disabling all higher orders of the auxiliary transfer mechanism. As shown in Fig. 3, the member I43 is adapted to be tilted to an ineffective position Whenever the highest inboard transfer lever 6| is actuated so as to enable the auxiliary transfer mechanism for the outboard orders to function to effect any required tens-transfer operation therein.

oscillatory movement of the shaft I34 .is effected by means of a cam I 48 mounted on a cam shaft Me journalled between the end plate I35 andthe bracket I36. Engaging with the cam M8 is a grooved roller I59 slidably and rotatably mounted on a pin which is mounted on an arm l5! secured to the shaft I32.

Reciprocatory movement of the shaft IE9 is effected by a drum cam I52 (Fig. 4) mounted on the left-hand end of shaft I i-Q, this cam having a sinuous groove I53 formed therein which is engaged by a pin (Fig. 3) secured to the shaft I34. pin normally lies midway along one of the inclined portions of the groove I53 so that upon rotation of the cam shaft I49 in either direction the actuator shaft I34 is first shifted endwise one-half step in one direction or the other, after which the shaft is rocked by cam I48 during the dwell provided in the groove I53. The actuator shaft E35 is then shifted longitudinally a fullstep in the opposite direction so as to provide an actuating stroke for the actuating teeth I33, after which the shaft is rocked by the cam I48 so as todisengage the actuator teeth from the gears I'St. The shaft I3 is then shifted one-half step in a longitudinal direction so as to return this shaft to its starting position.

' The cam shaft I49 carries a long pinion I 58 (Fig. 4) which is engagedby a small gear I59- j'ournalled on a stud I66 supported on a bracket I-GI (Fig. 3) attached to the left side frame '22. Gear I59 meshes with a large gear I62 which is journalled on a stud I 63- carried by abracket I64- w-hich is attached'to-the left side frame. Secured to the gear I62 is asmall gear '8 65 which meshes with a'large gear [63 fastened on the left-hand end of astub shaft I6! which is jouinalled in a bushing mounted in the left side frame 22'. Secured to the right-handend of the shaft I6! is a ten tooth gear I63 which is adapted to engage with one or'the other of a pair of ten tooth gears lfifl 'mountecl on either end of a sleeve which is slidablybutinon-rotatably mounted on a square shaft H0 which is" journalled at its forward end inthecrossbarztand at its rear end in a bracket I 'H- fastened to the framework of the machine. The selective engagement ofone or the other iscon-trolled from the gate shaft 575- by means of an arm I'iZ- mounted on the left-hand end of this shaft, which arm is. connected by a link 9 dition or subtraction, one or the other of the gears I69 will be engaged with the gear "38 so as to cause rotation of the cam shaft M9 in the appropriate direction.

Secured to the forward end of the square shaft I (Fig. 3) is a gear it!) which is adapted to be operated by a pawl it! (see also Fig. 2) which is apertured to receive an eccentric l8! secured to the forward end of the leftmost actuator shaft 4|. The lower end of the pawl I8! is provided with a slot which engages with a stud 83 mounted on the crossbar 2d. Hence, for each operation of the transverse power shaft 45, the pawl l8! will be given one complete cycle of movement whereby a tooth i865 (Fig. 2) formed on the upper end of the pawl it! will engage with the teeth of the ten tooth gear its and hence rotate the shaft I10 through one tenth of a revolution. In the event the gears ltfi are shifted, from the rocking of the plus-minus gate 55 and linkage I12, I13, I 14, a similar rotation of shaft I67 and gear I66 will be accomplished. The gear ratio between the shaft i5? and the cam shaft M9 is such that for each one-tenth revolution of the shaft IS! the cam will receive one complete rotation. Hence, on each cycle of the machine the actuating teeth I33 will be given one complete operation thereby causing any required transfers the outboard orders of the accumulator to be effected.

Division control mechanism in the present machine, mechanism is provided whereby a dividend set up on the accumulator Wheels 25 may be automatically divided by the method of successive subtraction by a divisor set up on the amount keys 35. As hereinbefore stated, this mechanism is similar to the mechanism shown in Fatent No. 2,327,981 and accordingly, only so much of this mechanism will be described as is necessary for a compl te understanding of the present invention.

The division control mechanism operates to control the functioning of the machine so as to cause the divisor to be repeatedly subtracted from the dividend until an overdraft occurs in the accumulator whereupon, the divisor is added back into the accumulator so as to correct the overdraft the or age is then shifted one ordinal space to the left, after which the process is repeated. The number of subtraction cycles effooted in each order is registered in the revolutions counter so as to provide a representation of the quotient at the end of the division operation. During division problems the machine is controlled by a program control device which becomes effective each time an overdraft occurs in the accumulator to program the operation of the add-subtract mechanism and also the carriage shift mechanism so as to cause the proper sequential operation of these mechanisms during uninterrupted, cyclic operation of the machine. The machine is conditioned for division by the depression of a division key which causes the program control device to be operatively connected with the add-subtract gate and the carriage shift mechanism and renders the overdraft control mechanism effective to control the cycling of the programming device.

As shown in Fig. 5, a division key [93 is mounted for sliding movement on the control plate H5 .and is provided on its lower end with an inclined cam face lei which bears against a roll i92 mounted on a division release slide E93. Referring to Fig. 6 of the drawings, it will be seen 10 that the slide I93 carries a roll I94 which lies in front of a finger l95 on a latch I95 pivotally mounted on a stud is? secured to the control plate I8. The latch I95 is normally urged counter-clockwise by a spring W8 so as to maintain a shoulder formed thereon beneath a stud I99 mounted in the forward end of an arm 200 which is pivoted on a stud 25E fastened to the control plate iii. The arm 2% is biased in a counter-clockwise direction by means of a heavy spring 2%? which serves to set or actuate the division control mechanism when the arm 250 is released by the latch :56. As shown in Fig. 5, when the division key its is depressed, the inclined cam face Edi will cause the slide 193 to be moved rearward whereby the roll fil -l will rock the latch E95 (Fig. 6) clockwise thereby releasing the actuating arm 2% for operation so as to cause setting of the division control mechanism.

The arm 205 is arranged to be restored during the first cycle of operation of the machine by means of a pin 265 mounted on the face of a gear 206 which is fastened on the right-hand end of the power shaft 45. The pin 265 is designed to cooperate with an inclined surface formed on the upper end of an arm 29'! which is integral with the arm 200.

Means is also provided for causing the clutch to be engaged and the motor contacts to be closed simultaneously with the release of the arm 200 from the latch i96. For this purpose a roll 208 (see also Fig. 5) bears against the underside of the arm 20%) so that when the latch I96 is released the roll 258 will be forced downwardly. The roll 263 is mounted on the lower end of a link 209 which is pivotally connected at its upper end to one arm of a bell-crank lever 2H1 which is pivoted on a screw 2 fastened to the control plate 19. The bellcrack lever has an upstanding arm which lies in front of a pin 2l2 on the forward end of the cycle initiating slide 88. As previously described, the slide 88 cooperates with the pin 89 to cause the motor contacts to be closed. and the clutch to be engaged so as to cause cycling of the machine.

As previously indicated herein, means is provided for operatively connecting the add-subtract gate with the program controlling device and for this purpose a connecting lever 2l8 is provided. As shown in Fig. 5, the lever 218 is pivoted at 219 on a cam follower arm 220 which is pivotally mounted on a stud 22i secured to the control plate '19. The forward end of the lever 2 i8 is pivotally connected at 222 to the lower end of the link 209 so that when this link is moved down following the depression of the division key I90, the rear end of the lever 2l8 will be moved upwardly so as to cause an inclined surface 223 formed thereon to engage with a pin 224 mounted on the control slide 84. The control slide will thereby be moved forwardly so as to cause the subtract gears 52 to be engaged with the gears 53 thereby conditioning the machine for subtraction. At the completion of the rocking movement of the lever 2i8, the pin 224 will be seated in the bottom of the notch 225 provided in the rear end of the lever 2 l3 thereby fully coupling the gate control slide84 with the cam follower arm 200.

During division operations, when the program controlling device is active, the movement of the control slide 84, and thereby the add-subtract gears 55, 52, is controlled by a wide-faced cam 226 which is secured to a program control shaft 221. As shown in Fig. 2, the shaft 221 extends 11 transversely across the width of the machine and is journalled in the left side frame 22', the right side frame 23 and the control plate 19.

By means later to be described herein, the shaft 221 is adapted to be given three steps of movement at the end of each cycle of operation of the machine following the advent of an over draft in the accumulator. As shown in Fig.

when the shaft 221 and cam 226 are in the positiond esignated by the line marked A, the connecting lever 218 will be located in its forward position where the subtract gears 52 will be engaged with the gears 53. At the end of the machine cyclein which an overdraft occurs, the shaft 221 will be rotated one-third of a revolution to the position marked B so as to cause the lever 2| 8 to be moved rearwardly and thereby cause the add gears 5! to be engaged with the gears 53. The divisor will thereby be added back into the accumulator so as to correct the overdraft and at the end of this cycle the shaft 221 will be rotated through a one-third of a revolution to the position marked C so as to move the connecting lever 2m to an intermediate or neutral position where the add-subtract gears 5t, 52 will be disengaged from the gears 53 and at the same time the carriage shift mechanism will. be rendered operative so as to cause shifting of the carriage through one ordinal space. At the end of the carriage shift cycle, the shaft 221 will again be rotated through one-third of a revolution so as to return the cam 22% to the position marked A. The machine will thereby once again be set for subtraction so as to cause the divisor to be repeatedly subtracted from the dividend until an overdraft again occurs whereupon the program control shaft 221 will once more be rendered active to control the machine through three cycles of operation in the manner indicated above.

This process will be repeated until the carriage reaches its end position whereupon the division operation will be terminated and the machine will come to rest with the quotient appearing on the revolutions counter wheels, 30.

Automatic division stop As indicated above, the division. operation will be automatically concluded when the carriage reaches its left end position, and for this purpose a pawl 233 (see Figs. 5, 13 and 14) is pivotally mounted in the framework of the carriage and is normally urged clockwise as viewed in Fig. 14 by means of a suitable tension spring 23L This pawl is adapted to cooperate with the upper end of a latch 232 (see Figs. 13 and 14) which is pivoted at 233 on the right side frame 23. The lower end of the latch 232 is provided with a shoulder which is adapted to engage with a half-round stud 234 (see also Fig. 5) carried by the connecting lever 258 so as to cause this lever to be held in its rocked position throughout the division operation. When the carriage shifts into its left end position the upper end of the latch 232 will contact the left-hand edge of the pawl 23!) (Fig. 13) and thereby rock the pawl counterclockwise as viewed in Fig. 14 against the tension of the spring 23!. Followin the shift cycle, the machine will again be set for subtraction until an overdraft occurs whereupon the connecting lever 2l8 will be moved rearwardly for the add-back cycle. The upper end of the latch 232 will thereby be moved forward whereupon the spring 23'! (Fig. 14) will rock the pawl 230' clockwise so as to move the forward end thereof to fi p s ti shown. in Fig, l4v in which it is behind the latchv 232.. At the end of the add-back cycle the conneoting lever'will be: moved forward so as to move.- the gate to its neutral position and, inasmuch as the upper end of the latch 232 is held against rearward movement by the pawl 230, as shown in Fig; 13, the stud 234 will move forward off of the shoulder on the latch thereby permitting the connecting lever 2 8 to drop to its inactive position. The cycle initiating slide 88 (Fig. 5) will thus be released whereupon it will move forwardly thereby breaking the motor circuit and disengaging the clutch.

Revolutions counter reversing mechanism In order to cause the subtraction cycles of the machine to be counted in a positive sense during division operations, it is necessary that the revolutions counter be operated in a reverse direction, and for this purpose a counter reversing key 238 (Fig. 6) is mounted on the control plate i9 so as to lie beside the division key I98. The key 238 is arranged to operate a counter reversing mechanism indicated generally at 239 so that when the key 233 is depressed along with the division key :99, a positive registration of the quotient will be caused to appear in the counter wheels 33. The counter reversing mechanism 239 and the means by which it is controlled by the key 238 is fully shown and described in U. S.

Patent No. 2,294,111, issued to Carl M. F. Friden on August 25, 1942, and reference is made to this patent for a disclosure of this part of the machine.

Division aligner mechanism In order to cause the dividend and divisor factors to be brought into alignment with one another at the beginning of a division operation means is provided in the machine presently being described for causing the carriage to be shifted toward the right until the factors are brought into alignment, after which the machine will proceed to automatically divide the dividend by the divisor. The novel mechanism hereinafter to be described for causing the dividend and divisor to be automatically aligned upon depression of the division key makes use of the previously described program control device for causing the carriage to be shifted to the right until the factors are aligned. The right shift operation is then terminated and the machine conditioned for an automatic division operation with left-hand shifting of the carriage.

In order to condition the program control mechanism so as to cause right-hand shifting of the carriage at the outset of the division operation the program control shaft 221 is arranged to be shifted axially from a neutral or inactive position to a left-hand position in which it will cause right-hand shifting of the carriage during each cyclic operation of the control shaft. The shaft 221 will remain in this position until the factors are properly aligned whereupon it will automatically be shifted axially to the right to a right-hand position in which it will control functioning of the machine in the normal manner for a division operation. As shown in Figs. 2, 6, 9, 11 and 12, the program control shaft 221 is provided on its right-hand end with a mutilated gear 245 which is similar in every respect to the mutilated gear shown and described in Patent No. 2,327,981. When the machine is at rest and the parts are in the positions which they normally occupy prior to the outset of a division operation, the mutilated gear 245 normally lies in an intermediate position as indicated by full lines in Fig. 2 and by dotted lines in Fig. 11. When the gear is in this position it lies between two spaced-apart, larger mutilated gears 258 and 241, each of which corresponds to the larger mutilated gear shown and described in the abovementioned patent. These gears are each provided with a single set of two teeth which are arranged to cooperate with the three sets of three teeth each provided on the mutilated gear 255 so as to effect an intermittent drive of this gear and of the control shaft 221. The gears 246 and 24 are secured to one another and also to a conventional type of gear 248 and the entire assembly is journalled on a screw 259 secured to the control plate 79. The gear 248 meshes with the gear 206 secured to the right-hand end of the power shaft 45 thereby providing a driving connection from the power shaft to the gears 245 and 241.

When a division operation is initiated by depression of the division key I92, a link 25? which is pivotally connected at its forward end to the arm 201 (Fig. 8) and guided at its rear end by a pin and slot connection 244 will be moved forwardly and will cause a pin 25! mounted on the link to rock an arm 252 pivoted on the control plate at 253 counter-clockwise against the action of a spring 255. The arm 252 is provided with a. camming face 255 which lies beneath a pin 255 mounted on a lever 251. The lever 25?! is secured to the left-hand end of a shaft 252 journalled between the control plate and the right side frame 23 and is normally held in the position shown in Fig. 6 by means of a spring 259 which resiliently holds a tail 266 of the lever in contact with a stud 26! on the control plate. The lever 25? is also provided with a forwardly extending arm 252 which carries a block or pad 263 on which is mounted a pin 285. In the normal position of the parts as shown in Figs. 2 and 6, the pin 26 i lies within a notch provided in the mutilated gear 225 and thereby locates the gear in its home position. The mutilated gear is also resiliently held in any one of its moved positions by means of a leaf spring 255 fastened to the control plate.

When the link 252 moves to the left, as viewed in Fig. 6, the arm 252 will be rocked counterclockwise so as to cause the pin 255 to be cammed upwardly where it will be held by a surface 2% provided on the arm 252. The parts will thereby be positioned as shown in Fig. 12 with the pin 264 disengaged from the notch in the mutilated pinion.

On the forward end of the arm 292 is a pin 2?! which is adapted to cooperate with a crescentshaped cam 2'52 fastened to the inner face of the gear 2 35. When the lever 25? is in its normal position, as shown in Fig. 6, the cam 222 will bypass the pin 2'5 l, but when the lever has been ele vated to the position shown in Fig. 12 the pin will be engaged by the outer periphery of the cam thereby causing the lever 25? to be rocked to the position shown in Fig. 9. ihe pad 223 on the lever is thereby moved out from behind the mutilated gear thereby permitting the shaft 221 to be shifted to the left under the influence of a compression spring 215 (Fig. 2) located on the left-hand end of the shaft. The mutilated gear 245 will thereby be brought into the plane of the larger mutilated gear 246 so as to initiate cyclic operation of the control shaft 22l.

The lifting of the arm 262 into the position shown in Fig. 9 also raises the stud 256 off of the face 210 thereby allowing the spring 254 to restore the arm 252 to the position shown in Figs. 6 and 9 where the arm is once again held in contact with the pin 25! on the link 259. At the time that the arm 252 is released by the pin 256, the link 250 will have been restored to its original position due to the restoration of the actuating arm 232 by the pin 205 on the gear 205 (Fig. 6). Once the mutilated gear has been shifted to the left in the manner described, the pad 253 on the lever 25'! will be prevented from again engaging behind the gear upon release of the pin 27! by the cam 212, the lever being merely permitted to move down until a curved portion Zlfi of the pad rides on the outer ends of the gear teeth on the mutilated gear.

As shown in Fig. 11, the cam 225 is of sufficient width that it will always remain engaged with the aperture in the follower arm 22c during axial shifting movements of the shaft 221.

Right-hand shifting movement of carriage is effected under the control of the shaft 22! by means of a cam 21! (Fig. 2) secured to this shaft which is adapted to cooperate with an arm 228 secured to a hub 219 freely rotatable on a. shaft 282 journalled between the right side frame 23 and a bracket 28l secured to the supporting bar 42. Also secured to the hub 275} is a shifter arm 222 which is adapted to cooperate with the right shift fork H l and cause this fork to be moved rearwardly when the shifter arm is rocked clockwise as viewed from the right-hand side of the machine. The assembly consisting of the arms 218 and 282 and the hub 2l9 is held against endwise movement on the shaft 282 by a pair of collars 283 which are pinned to the shaft.

Secured to the connecting lever 218 is a long pin 285 (Figs. 2 and 5) which extends through an aperture in the right side frame 23 and lies beneath the forwardly extending arm of a bellcrank lever 286 which is pivoted at 28'! on a bracket 288 fastened to the right side frame. The lever 285 is provided with an upwardly extending shifting arm 289 which engages between a pair of spaced flanges formed on a hub 22%} secured to the right-hand end of a shaft 28 Consequently, when the connecting lever is rocked clockwise as viewed in Fig. 5 upon depression of the division key I82, the pin 235 will rock the bellcrank 286 counter-clockwise as viewed from the front of the machine thereby the shifting arm 282 to move the shaft 269 laterally against the force exerted by a compression spring 25H mounted on the left-hand end of the shaft. This will cause the follower arm 2l2 to be moved to the left where it will lie out of the of the shift cam 2?? when the program control shaft 22? is in its intermediate position with the mutilated gear lying midway between the gears 245 and 241, as shown in Fig. 2. However, when the mutilated gear is released by the arm for left-hand movement under the influence of the compression spring 215, the cam Ell will be shifted to the left and once more be brought into alignment with the follower 2'58. Hence, when the control shaft 221 is rotated to the position indicated at C in Fig. 5, the cam 2?? will be rotated into position to rock the arm clockwise as viewed from the right side of the ma chine and to hold it in this position during the shift cycle. The shifter arm 282 will also be held rocked during the shift cycle so as to cause the right shift clutch to be maintained operative and 15 hencev cause the carriage to be shifted one space to the right.

So long as the mutilated gear lies in the plane of the larger mutilated gear 246, the program control shaft 227 will be continuously cycled soas to cause the machine to be given an add-back cycle followed by a shift cycle during which the carriage is moved one space to the right. The shift cycle will in turn be followed by a subtract cycle during which the divisor will be subtracted from the dividend. This sequence of operations will be continued until an overdraft occurs in the accumulator thereby indicating that the carriage hasbeen shifted sufiiciently far to the right to bring the dividend and divisor into proper alignment for-division. Mechanism is then brought into play for causing the machine to operate through an automatic division operation in the normal manner.

As shown in Fig. 8, the highest order accumulator wheel shaft 54 is provided with a cam 295 which is arranged to cooperate with a tooth 236 formed on a bar 29?. The bar 29'! is fastened at either end to the side arms 238 of a bail 299 which is pivotally supported at either end on brackets 36!! which are secured to the crossbar 63 of the carriage frame. The bail 2% is engaged by the notched end of a lever 3t! (see also Fig. 3) which is pivotally mounted on a screw 322 fastened to the left side plate 22. arranged to be retained in either of two positions by a detent lever 3 33 which is pivoted on the gate shaft and urged into engagement with one or the other of two notches provided on the lower end of the lever 393i by means of a spring 304. The lever 31H carries a pin 305 which passes through an aperture provided in the left side frame and has pivotally secured thereto an overdraft control link 366 (see also Fig. 10) which is supported at its forward end by a pin 367 which engages with an elongated slot provided in the link. The pin Sill is carried by an arm 3% which is secured to a transverse shaft 339 (Fig. 2) which is journalled between the left side frame 22 and the control plate '19. At its right-hand end the shaft 309 has secured thereto an arm 3) the forward end of which lies above the pin 285 on the connecting lever 2l8. Hence, when the rear end of the connecting lever is elevated upon the initiation of a division operation, the shaft 3% will be rocked clockwise as viewed from the right side of the machine thereby causing the pin (Fig. 10) to lift the forward end of the link 336 to a position where it will lie behind an overdraft control flag 3 which is shaped in the form of a bail and loosely pivoted on the control shaft 227 (see also Fig. 2). Hence, after the carriage has been shifted sufficiently far to the right to cause an overdraft in the accumulator when the divisor is subtracted from the dividend, the cam 295 on the highest order numeral wheel shaft (Fig. 8) will engage with the tooth 296 as the wheel moves from 0-9 thereby rocking the bail 299 rearwardly so as to cause the pin 385 and the overdraft control link 3526 (Fig. 10) to be moved forward and cause the flag 3!! to be rocked clockwise as viewed in Fig. 10. At the end of the cycle in which the overdraft occurred, the control link 306 and the lever 30! will be restored to their normal positions by means of a cam 352 secured on the left-hand end of the transverse power shaft 45. As shown in Fig. 10, this cam is provided with a nose which is adapted to cooperate with a roll on an arm 3l3 which is provided on the left side frame 22. The lower The arm 36! is forward end of a link 3M which is provided at its rear end with an elongated slot which engages over the stud 305. Hence, shortly after the control link 3136 has been moved forward near the end of a subtraction cycle, the nose on the cam 3E2 will contact the roll on the arm M3 and force the link 306 and the lower end of lever 30] rearwardly where they will be retained by the spring-urged detent 303. The forward movement of the overdraft control link 326 and resulting clockwise rocking of the flag 3| I, efiected by an overdraft as described above, will bring an upstanding finger 315 (see Figs. 1 and 2) on the flag into the path of a pin 3H6 provided on the forward face of a disc 3|! secured to the leftmost actuator shaft 45. The pin 318 will engage with the finger 3l5 near the end of the cycle in which the overdraft occurred so as to shift the flag toward the right. This will cause the control shaft 221 to be likewise shifted to the right, by virtue of a collar 3H3 secured to the shaft 221, displacing the cam 211 from operative relation with the right shift follower arm 278. The rightward shifting of the shaft 227 will also cause the mutilated gear 2A5 to be brought into the plane of the larger mutilated gear 2 so as to cooperate with the single set of three teeth thereon. These teeth will cooperate with the mutilated gear 245 at the very end of the overdraft cycle and cause the control shaft 227 to be rotated through one-third of a revolution so as to condition the machine for addition. At the end of the addition cycle the control shaft 22'! will receive another degrees of rotation so as to condition the machine for a left shift operation which is accomplished in the machine presently being described by means of a shift cam 323 secured to the control shaft 227 which is brought into the plane of a follower arm 32! when the shaft is shifted to the right. The fol lower arm 32l is secured to the hub 290 so that when the arm is rocked clockwise by the cam, the shaft 280 will likewise be rocked in the same direction. Secured to the shaft 238 is a left shifter arm 322, the rear end of which bears against the left shift fork H2. Hence, when the arm 322 is rocked clockwise the left shift clutch will be engaged and cause the carriage to be shifted one ordinal space to the left.

When the control shaft 22? and the mutilated gear 2% are shifted to their right-hand positions by the flag 3! i, the gear will be moved out from beneath the pad 253 on the lever 25'? thereby permitting the lever to be rocked counter-clockwise by the spring 253 into the position shown in Fig. 6. This will occur near the end of the machine cycle so that the cam 2l2 will lie in substantially the position shown in Fig. 6. The pin 26%, however, will not be permitted to engage with the notch in the mutilated gear inasmuch as the gear has been shifted sufficiently far to the right that it lies beyond the end of the pin 254. After the mutilated gear has been rotated through onethird of a revolution and the flag 353 has been released by the pin 35%, the spring 2i5 on the left-hand end of the control shaft 22'? will urge the mutilated gear toward the left so as to bring the left-hand face of the gear against the end of the pin 2% and the gear will continue to ride on this pin until the control shaft has made one full revolution whereupon the notch in the gear will drop over the pin and the mutilated gear and control shaft will be moved by the spring 215 to the left into their intermediate positions,

17 as shown in Fig. 2. At this time the machine will be conditioned for subtraction and the divisor will be repeatedly subtracted from the dividend until an overdraft again occurs in the accumulator whereupon the finger 3E5 on the flag will be moved into the path of the pin SIS so as to cause the control shaft to again be moved to the right for another cycle of operation during which time it will control the machine through an add-back cycle followed by a left shift cycle which in turn i followed by a subtraction setting of the addsubtract gate which setting will be maintained until an overdraft again occurs in the accumulator. This process will be continued until the carriage reaches its left end osition whereupon the operation will be terminated by the pawl. mounted on the right-hand end of the carriage.

When the shaft 22? and mutilated gear 245 have been moved to the left to their intermediate positions, shown in Fig. .2 to condition the machine for repeated subtraction, the right shift cam 21? on the shaft 22? will not be moved into operative relation with the right shift follower arm 218, because the latter remains in its leftward displaced position under the control of the pin 285 on the connecting lever 218, and the bell crank 286. Hence, the repeated subtraction will take place while the right shift mechanism remains disabled.

In some instances, a division operation may be stopped before being completed, as for example by operation of manually controlled division stop mechanism, leaving the shaft 22'. and the left shift cam 326 shifted to the right. In such cases it is necessary that, in the stopped positions of the parts, the left shift controlling cam 32:: and the left shift follower arm 32i be in different planes so that no premature automatic shifting will take place in the next machine operation. This is provided for by so positioning the follower arm 32! on the shaft 250 that in the normal or non-actuated positions of all of the parts, except for the shaft 22'! and cam 32! standing shifted to the right, the follower arm 32! is spaced to the right of the cam 2-29, even though the shaft 22? stands shifted to the right. However, the initial shifting of the shaft 280 and the follower arm 32% to the left, effected when the division key I90 is depressed, makes it possible for the rightward shifting of the shaft 22? to move the cam ezc into the plane of the follower arm 32L Unles means were provided for disabling the pawl 23d (Figs. 5, 13 and 14) upon depression of the division key, it would be impossible to latch the connecting lever 2H in its rocked position due to the latch 232 being held disabled by the pawl 23b. The means for disabling the pawl upon depression of the division key I98 consists of a slide 325 (Figs. and i l) which bears a pin 326 lying behind the rear end of the cycle initiating slide 88. Hence, when the latter slide is moved toward the rear upon depression of the division key, the slide 325 will also be moved rearwardly. On the rear end of the slide 325 i mounted an extension on which is pivotally mounted a pawl 328 which is provided at its rear end with a notch for engaging with a pin 329 carried by the pawl The pawl 328 is normally urged to rotate in a clockwise direction as viewed in 14 by means of a spring 338 which is stretched between an car on the pawl and an ear formed on th extension 32?.

When the carriage approaches its extreme left hand position, while the slide 325 and pawl 328 are displaced rearwardly from the positions shown 18 in Figs. 5 and l i, the pin 322 on the pawl 230 will engage the right hand face of the pawl 328 at a point between the pivotal mounting of the pawl $23 and the notch in this pawl. The pawl will yield counterclockwise, as viewed in Fig. 14, due to the resiliency of the spring 335 and thus will not interfere with left shifting movement of the carriage and the aw to their extreme left hand positions. At this time the 1)" vi 2 58 also will rock counterclockwise from its 1 position because of the front part of the engaging the right hand face of the as shown in Fig. 13. The right the pawl in front of the notch, against the pin 329, tending However, when the latch lever 232 is rocked counterclockwise as viewed in Fig. 13, incident to operation of the division slopping mechanism, the relatively strong spring .135 will rock the pawl 23?) clockwise as viewed in Fig. to position it behind the latch lever as shown in Fig. 14 because the spring Bill is strong enough to overcome the relatively weak spring 336 which is then urging the right hand face of the pawl 328 in front of the notch, into contact with the pin 329, thus tending to prevent the pawl 2150 from returning to its Fig. 14 position. When the operation stops, the slide 32%": will be moved forwardl and the spring will move the pawl 323 to its Fig. 14 position wherein the pin 329 is received in the notch of the pawl The machine will then be conditioned to be started when the slides 88 and are displaced rearwardly.

At the end of division operations terminated by the automatic division stop means, the cycle controlled the mutilated gear 245 has not been completed and the gear is not moved from registration with the gear 241. In order to prevent initiation of a division operation with the parts so relatively positioned, the mutilated gear is provided with a blocking part in the form of a hub 3-35 which will lie in the path of and will restrain a finger 336 formed on the upper end of the arm 25? when the mutilated gear is in this position. Hence, as shown in Fig. 6, the arm 252 will be blocked against counter-clockwise movement by the pin 255 on the link 25B thereby preventing movement of the actuator arm 2% under the influence of its spring 282. However, when the mutiliated gear is in its intermediate position, the finger 335 will be free to move past theend of the hub 335 thereby enabling the initiation of a division operation upon depression of the division key I90.

The setting of the divisor on the keyboard and the dividend in the numeral wheels may be such that the highest order numeral wheel will not be rotated through zero during the subtraction cycle with the carriage in its extreme right-hand position. In this case the divisor would be added into the accumulator, the right shift clutch engaged though no further shifting could occur, and the divisor again subtracted from the same orders of the accumulator as before. Hence, the mach ne would, in effect, be stalled in it right end position would continue cycling in this position until brought to a stop by the manual division stop lever hereinafter to be described.

In order to prevent this contingency from occurrin the conventional override pawl 35;? (Fig. 7) mounted on the shift rack l22 (see Patent No. 2,327,635, supra) is provided with a camming tail on which is formed an inclined lip 339. The end of the tail 333 lies immediately in front of the inboard side arm 293 of the bail 299- so that when the pawl is rocked clockwise as viewed in Fig. 7 by one of the shift pins l2l (Fig. 2), the lip 339 will engage the side arm and cam the bail 299 toward the rear of the machine. This will have the same effect as the rocking of the bail by the cam 2th": on the highest order numeral wheel, i. e., the flag 335 will be thrown in and the mutilated gear shifted to the right so a to initiate a conventional division operation with left-hand shifting of the carriage.

Manual division stop mechanism Manually operable mechanism, shown in Fig. 13, is provided for stopping the machine either at the end of a current cycle or following an addback cycle phase during division. If the stop mechanism is operated when the machine is not dividing, the machine is first conditioned for one dividin cycle Which is followed by stopping of the machine.

ilhe mechanism shown includes a manually operable stop lever S it pivoted as at 34! on the plate 23 so as to be r-ockable either clockwise, that is rearwardly of the machine, or counterclockwise, that is forwardly of the machine. A spring-urged detent 362 is provided for yieldingly retaining the stop lever 35% in its forward position. The lever 355i is formed with an inclined cam nose 3% normally overlying an ear 347 on the latch 232.

The parts of the stop mechanism thus far described may be operated to stop the machine at the end of a current cycle if the program control shaft 22? is not in its left-hand position for effecting rightward or aligning shifting of the carriage. When the shaft 22? is not in its lefthand position, the control shaft 258 is in its unactuated position, i. e. the position shown in Figs. 2, 6 and 13. In order to stop the machine, the lever 3453 is rocked clockwise as viewed in Fig. 13, causing the cam nose 348 to press upon the ear 347 and deflect it rearwardly, thus rocking the latch 232 counterclockwise from its Fig. 13 position so as to release the pin 234 on the connecting lever 258, thus permitting the latter to be returned to its normal position and causing the machine to stop at the end of the current cycle.

Means is provided for preventing the lever 34! from being rocked clockwise when the shaft 227 is in its left-hand position and the control shaft 255 is in its actuated position as shown in Fig. 9. Referring to Fig. 13, the shaft 258 is fast with an arm 3% formed with a slot see which receives a pin 355 on another arm 35s pivoted as at set on the plate 23. The arm 359 is provided with a pin 38: adapted to be moved into a slot 362 in the lower end of the stop lever 34%, the slot 352 being formed with inclined entrance portions 363 and 36 for guiding the pin 36E into the slot 362 when the arm 35-9 is rocked counterclockwise from its Fig. 13 position. When the shaft 253 is moved to its actuated position the arm 349 is rocked clockwise and, through the slot 356 and the pin 35!, the arm 359 is rocked counterclockwise so as to move the pin 365 into the slot 362 at the bottom of the lever S id. The relative positions of the pivots 3M and the slot 352 and the pin 36! will then be such that the arm 359 will block the stop lever against clockwise rocking. However, if the program control shaft 221 is not in its left-hand position, the shaft 258 will be in its unactuated position as shown in Fig. 13, and the pin 36! will be clear of the slot 362, thus 20 enabling the lever sec to be rocked clockwise to stop the machine at the end of a current cycle in the manner described above.

Mechanism is provided for stopping the machine, not necessarily during a current cycle, but after the first add-back cycle following movement of the stop lever 3% forwardly, i. e. counterclockwise. As shown in Fig. 13 a pawl 343 is pivoted on the plate 23 as at 3 5i and is provided with a pin 334 which extends through a slot in the stop lever 3 3%. A spring 345 interposed between an ear on the stop lever 34% and the pin 3% urges the pawl 3G3 counterclockwise so as normally to hold the pin 3% against the right end of the associated slot. The pawl 343 is formed with a shoulder 3:35 normally disposed below an ear 347 on the latch 232. The stop lever ass is formed with an car 352 underlying an arm of a bell crank 35 i pivoted at 355. The bell crank 3545 has another arm equipped at it lower end with a conical pin 35?. Normally, when the parts are in the positions shown in Fig. 13, the pin 35? is disposed radially O1 laterally beyond the path of a bevelled cam 358 on the program control shaft 227.

When a division operation is being performed the parts will be in the positions shown in Fig. 13, the pin 3M being clear of the slot 362 in the stop lever S it and the program control shaft 22? being displaced to the right, so that the cam 358 will stand displaced axially from the pin 351. Counterclockwise rocking of the stop lever 346 will move the lower end of the pawl 363 against the ear 3 37 on the latch 232 so as to tension the spring 3515. The detent 3 32 will then act to hold the lever in its rocked position. When an add-back cycle occurs, causing the connecting lever H8 and the pin 23 i thereon to be moved rearwardly, the latch 232 will be rocked counterclockwise so as to permit the spring 335 to rock the pawl 3- 53 counterclockwise, and move the shoulder 3&6 thereon above the car 34? on the latch 232. When the connecting lever M8 and pin 234 move forwardly following the add-back operation, the iatch 232 will be held in its rocked position by the pawl 333, causing the pin 234 to be disengaged from the latch 232, thus enabling the connecting lever 2 i8 to return to its unactuated position so as to stop the machine.

If the program control shaft 227 is in its leftmost or aligning position when it is desired to stop the machine, the bevelled cam 358 will stand aligned with the conical pin 35?, and the pin 35! will be in. the slot 362 because of the shaft 258 and arm 359 thereon being in actuated positions.

Nevertheless, the relation of the parts is such that the stop lever 348 can be rocked forwardly without being blocked by the pin 36i and arm 359, the pin 3t! merely being cammed or slipped out of theslot 352. The forward rocking of the lever 3 5i acts through the car 352 to rock the bell crank 354 clockwise; and thus to move the conical pin 35? into the path of the bevelled cam 353. When the cam 358 engages the pin 35?, the cam and the program control shaft 22? will be shifted axially to, the right, thus conditioning the machine for a division operation. After the add-back phase of the ensuing division operation cycle, the pin 234 will be disengaged from the latch 232 which, at this time, will be held in its rearward position by the pawl S te in the manner previously described. Consequently the connecting lever 218 will be returned to its unactuated position and the machine will stop.

I claim:

1. A calculating machine capable of carrying out problems in division comprising an amount entering means on which the various digits of a divisor may be set; a carriage mounted for end wise shifting movement on said machine; means for shifting said carriage in either direction; a register comprised of a plurality of numeral wheels rotatably mounted on said carriage, said wheels being settable to represent the various digits of a dividend; means for successively subtracting the divisor from the dividend, adding the divisor back into the dividend, and shifting said carriage one step in a predetermined direction so as to bring the higher order wheels of said re ister into active position with respect to said amount entering means; and means activated by a predetermined change in the registration in the highest order numeral wheel of said register for terminating the operation of said shifting means in said predetermined direction when the dividend and divisor are correctly aligned for the performance of a division operation.

2. In a machine of the class described having a plural order value entering means for receiving a divisor value, a register shiftable relative thereto for receiving a dividend value, means for shifting said register in one direction to bring the higher orders thereof into alignment with said value entering means or in another direction to brin the lower orders thereof into alignment with said value entering means, and means for causing the divisor value to be added to or subtracted from the dividend value, the combination of a program control device for controlling the operation of said adding and subtracting means and said shifting means, said device having an idle position in which it is ineffective to control the operation of either of said means, a factor aligning position in which it is effective to successively cause the divisor value to be subtracted from the dividend value, to be added back therein and said register to be shifted one step in said one direction, and a dividing position in which it is effective to successively cause the divisor value to be subtracted from the dividend value, to be added back therein and said register to be shifted one step in said other direction; means for initiating a division operation; means controlled by said initiating means for moving said device from its idle position to its factor aligning position and maintaining it there until said register has been shifted in said one direction to its factor ai ing position; a tens-carry mechanism for cans g a unit to be transferred from one order of the register to the next; and means controlled by said tens-carry mechanism for causing said device to be moved from its factor aligning position to its dividing position when a carry is effected in the highest order of the register.

3. In a machine of the class described having a plural order value entering means, a carriage shiftable relative thereto, and a register mounted on said carriage, the combination of means for shifting said carriage in either one direction or another, said means including a right-shift clutch for shifting said carriage in the direction of decreasing orders of said register and a leftshift clutch for shifting said carriage in the direction of increasing orders of said register; a program control device for controlling the operation of said shift clutches, said device including a shaft capable of being shifted axially from an idle position to either a factor aligning position or a dividing position; means for rotating said shaft in either its factor aligning position or its dividing position; means controlled by said program. control device shaft in either the factor aligning or the dividing position thereof for entering values in said register; means on said shaft for causing said right-shift clutch to be engaged when said shaft is rotated in its factor aligning position and for causing said left-shift clutch to be engaged when said shaft is rotated in its dividing position; means for initiating a division operation; means controlled by said initiating for causing said shaft to be shifted from its idle position to its factor aligning position where rotation of said shaft by said rotating means will cause said right-shift clutch to be engaged; a tens-carry mechanism for causing a unit to be transferred from one order of the register to the next order thereof consequent upon a predetermined registration change in one of said orders; and means controlled by said tenscarry mechanism for causing said shaft to be shifted from its factor aligning position to its dividing position where rotation of said shaft by said rotating means will cause said left-shift clutch to be engaged.

4. In a machine of the class described for solving problems in division, the combination of means for receiving one of the factors of a division problem; means for receiving another of the factors of a division problem; means for shifting one of said factor receiving means relative to the other including a first clutch for shifting said one of said factor receiving means in one direction and a second clutch for shifting said one of said factor receiving means in another direction; means for selectively engaging one or the other of said clutches including a rotatable member shiftable along its axis of rotation to either of two positions; means for rotating said member in either of said positions; means for causing said first clutch to be engaged when said member is rotated in one of said positions and to cause said second clutch to be engaged when said member is rotated in the other of said positions; means for shifting said memher to its position for effecting engagement of said first clutch to effect shifting of said one of said factor receiving means to a position in which the division problem factors are aligned for the commencement of a division operation; means responsive to arrival of said one of said factor receiving means in the factor aligning position for shifting said member to its position for offecting engagement of said second clutch; and means for then performing a division operation.

5. In a machine of the class described having a plural order value entering means, a register shiftable relative thereto, and means for shifting said register in one direction so as to bring the higher orders thereof into alignment with said value enterin means or in another direction so as to bring the lower orders thereof into alignment with said value entering means, the combination of a program control device for controlling the operation of said shifting means, said device having an idle position in which it is ineffective to control said shifting means, a factor aligning position in which it is effective to cause said shifting to shift said register in said one direction, and a dividing position in which is effective to cause said shifting means to shift said register in said other direction; means controlled by said program control device in either its factor aligning position or its divid- 

